Abstract: Different consumer owns different preference and loyalty on different brands. If it is overlooked by researchers,the model without brand loyalty or SKU loyalty can't elicit the consumer heterogeneity and dynamics so that it can not improve the model fit. The paper proposed a dynamic Multinomial Logit choice model and calculated the brand loyalty and SKU loyalty of online consumers. It revealed following results:The panel data shows that different loyalties have different impact on online consumers brand choice and online consumer shows high SKU loyalty. It not only identified the heterogeneity of consumer purchase rate,but also improved the model fit. Though different attributes have impact on online consumer brand choice behavior,these impacts are not isolated,and varied with the other attributes and loyalty variables.

Key words: online consumer choice, brand loyalty, SKU loyalty, panel data